/**
 * @author mrdoob / http://mrdoob.com/
 */
const THREE = require('../../three.js');

(function () {

	const _object_pattern = /^[og]\s*(.+)?/; // mtllib file_reference

	const _material_library_pattern = /^mtllib /; // usemtl material_name

	const _material_use_pattern = /^usemtl /; // usemap map_name

	const _map_use_pattern = /^usemap /;

	const _vA = new THREE.Vector3();

	const _vB = new THREE.Vector3();

	const _vC = new THREE.Vector3();

	const _ab = new THREE.Vector3();

	const _cb = new THREE.Vector3();

	function ParserState() {

		const state = {
			objects: [],
			object: {},
			vertices: [],
			normals: [],
			colors: [],
			uvs: [],
			materials: {},
			materialLibraries: [],
			startObject: function (name, fromDeclaration) {

				// If the current object (initial from reset) is not from a g/o declaration in the parsed
				// file. We need to use it for the first parsed g/o to keep things in sync.
				if (this.object && this.object.fromDeclaration === false) {

					this.object.name = name;
					this.object.fromDeclaration = fromDeclaration !== false;
					return;

				}

				const previousMaterial = this.object && typeof this.object.currentMaterial === 'function' ? this.object.currentMaterial() : undefined;

				if (this.object && typeof this.object._finalize === 'function') {

					this.object._finalize(true);

				}

				this.object = {
					name: name || '',
					fromDeclaration: fromDeclaration !== false,
					geometry: {
						vertices: [],
						normals: [],
						colors: [],
						uvs: [],
						hasUVIndices: false
					},
					materials: [],
					smooth: true,
					startMaterial: function (name, libraries) {

						const previous = this._finalize(false); // New usemtl declaration overwrites an inherited material, except if faces were declared
						// after the material, then it must be preserved for proper MultiMaterial continuation.


						if (previous && (previous.inherited || previous.groupCount <= 0)) {

							this.materials.splice(previous.index, 1);

						}

						const material = {
							index: this.materials.length,
							name: name || '',
							mtllib: Array.isArray(libraries) && libraries.length > 0 ? libraries[libraries.length - 1] : '',
							smooth: previous !== undefined ? previous.smooth : this.smooth,
							groupStart: previous !== undefined ? previous.groupEnd : 0,
							groupEnd: - 1,
							groupCount: - 1,
							inherited: false,
							clone: function (index) {

								const cloned = {
									index: typeof index === 'number' ? index : this.index,
									name: this.name,
									mtllib: this.mtllib,
									smooth: this.smooth,
									groupStart: 0,
									groupEnd: - 1,
									groupCount: - 1,
									inherited: false
								};
								cloned.clone = this.clone.bind(cloned);
								return cloned;

							}
						};
						this.materials.push(material);
						return material;

					},
					currentMaterial: function () {

						if (this.materials.length > 0) {

							return this.materials[this.materials.length - 1];

						}

						return undefined;

					},
					_finalize: function (end) {

						const lastMultiMaterial = this.currentMaterial();

						if (lastMultiMaterial && lastMultiMaterial.groupEnd === - 1) {

							lastMultiMaterial.groupEnd = this.geometry.vertices.length / 3;
							lastMultiMaterial.groupCount = lastMultiMaterial.groupEnd - lastMultiMaterial.groupStart;
							lastMultiMaterial.inherited = false;

						} // Ignore objects tail materials if no face declarations followed them before a new o/g started.


						if (end && this.materials.length > 1) {

							for (let mi = this.materials.length - 1; mi >= 0; mi--) {

								if (this.materials[mi].groupCount <= 0) {

									this.materials.splice(mi, 1);

								}

							}

						} // Guarantee at least one empty material, this makes the creation later more straight forward.


						if (end && this.materials.length === 0) {

							this.materials.push({
								name: '',
								smooth: this.smooth
							});

						}

						return lastMultiMaterial;

					}
				}; // Inherit previous objects material.
				// Spec tells us that a declared material must be set to all objects until a new material is declared.
				// If a usemtl declaration is encountered while this new object is being parsed, it will
				// overwrite the inherited material. Exception being that there was already face declarations
				// to the inherited material, then it will be preserved for proper MultiMaterial continuation.

				if (previousMaterial && previousMaterial.name && typeof previousMaterial.clone === 'function') {

					const declared = previousMaterial.clone(0);
					declared.inherited = true;
					this.object.materials.push(declared);

				}

				this.objects.push(this.object);

			},
			finalize: function () {

				if (this.object && typeof this.object._finalize === 'function') {

					this.object._finalize(true);

				}

			},
			parseVertexIndex: function (value, len) {

				const index = parseInt(value, 10);
				return (index >= 0 ? index - 1 : index + len / 3) * 3;

			},
			parseNormalIndex: function (value, len) {

				const index = parseInt(value, 10);
				return (index >= 0 ? index - 1 : index + len / 3) * 3;

			},
			parseUVIndex: function (value, len) {

				const index = parseInt(value, 10);
				return (index >= 0 ? index - 1 : index + len / 2) * 2;

			},
			addVertex: function (a, b, c) {

				const src = this.vertices;
				const dst = this.object.geometry.vertices;
				dst.push(src[a + 0], src[a + 1], src[a + 2]);
				dst.push(src[b + 0], src[b + 1], src[b + 2]);
				dst.push(src[c + 0], src[c + 1], src[c + 2]);

			},
			addVertexPoint: function (a) {

				const src = this.vertices;
				const dst = this.object.geometry.vertices;
				dst.push(src[a + 0], src[a + 1], src[a + 2]);

			},
			addVertexLine: function (a) {

				const src = this.vertices;
				const dst = this.object.geometry.vertices;
				dst.push(src[a + 0], src[a + 1], src[a + 2]);

			},
			addNormal: function (a, b, c) {

				const src = this.normals;
				const dst = this.object.geometry.normals;
				dst.push(src[a + 0], src[a + 1], src[a + 2]);
				dst.push(src[b + 0], src[b + 1], src[b + 2]);
				dst.push(src[c + 0], src[c + 1], src[c + 2]);

			},
			addFaceNormal: function (a, b, c) {

				const src = this.vertices;
				const dst = this.object.geometry.normals;

				_vA.fromArray(src, a);

				_vB.fromArray(src, b);

				_vC.fromArray(src, c);

				_cb.subVectors(_vC, _vB);

				_ab.subVectors(_vA, _vB);

				_cb.cross(_ab);

				_cb.normalize();

				dst.push(_cb.x, _cb.y, _cb.z);
				dst.push(_cb.x, _cb.y, _cb.z);
				dst.push(_cb.x, _cb.y, _cb.z);

			},
			addColor: function (a, b, c) {

				const src = this.colors;
				const dst = this.object.geometry.colors;
				if (src[a] !== undefined) dst.push(src[a + 0], src[a + 1], src[a + 2]);
				if (src[b] !== undefined) dst.push(src[b + 0], src[b + 1], src[b + 2]);
				if (src[c] !== undefined) dst.push(src[c + 0], src[c + 1], src[c + 2]);

			},
			addUV: function (a, b, c) {

				const src = this.uvs;
				const dst = this.object.geometry.uvs;
				dst.push(src[a + 0], src[a + 1]);
				dst.push(src[b + 0], src[b + 1]);
				dst.push(src[c + 0], src[c + 1]);

			},
			addDefaultUV: function () {

				const dst = this.object.geometry.uvs;
				dst.push(0, 0);
				dst.push(0, 0);
				dst.push(0, 0);

			},
			addUVLine: function (a) {

				const src = this.uvs;
				const dst = this.object.geometry.uvs;
				dst.push(src[a + 0], src[a + 1]);

			},
			addFace: function (a, b, c, ua, ub, uc, na, nb, nc) {

				const vLen = this.vertices.length;
				let ia = this.parseVertexIndex(a, vLen);
				let ib = this.parseVertexIndex(b, vLen);
				let ic = this.parseVertexIndex(c, vLen);
				this.addVertex(ia, ib, ic);
				this.addColor(ia, ib, ic); // normals

				if (na !== undefined && na !== '') {

					const nLen = this.normals.length;
					ia = this.parseNormalIndex(na, nLen);
					ib = this.parseNormalIndex(nb, nLen);
					ic = this.parseNormalIndex(nc, nLen);
					this.addNormal(ia, ib, ic);

				} else {

					this.addFaceNormal(ia, ib, ic);

				} // uvs


				if (ua !== undefined && ua !== '') {

					const uvLen = this.uvs.length;
					ia = this.parseUVIndex(ua, uvLen);
					ib = this.parseUVIndex(ub, uvLen);
					ic = this.parseUVIndex(uc, uvLen);
					this.addUV(ia, ib, ic);
					this.object.geometry.hasUVIndices = true;

				} else {

					// add placeholder values (for inconsistent face definitions)
					this.addDefaultUV();

				}

			},
			addPointGeometry: function (vertices) {

				this.object.geometry.type = 'Points';
				const vLen = this.vertices.length;

				for (let vi = 0, l = vertices.length; vi < l; vi++) {

					const index = this.parseVertexIndex(vertices[vi], vLen);
					this.addVertexPoint(index);
					this.addColor(index);

				}

			},
			addLineGeometry: function (vertices, uvs) {

				this.object.geometry.type = 'Line';
				const vLen = this.vertices.length;
				const uvLen = this.uvs.length;

				for (let vi = 0, l = vertices.length; vi < l; vi++) {

					this.addVertexLine(this.parseVertexIndex(vertices[vi], vLen));

				}

				for (let uvi = 0, l = uvs.length; uvi < l; uvi++) {

					this.addUVLine(this.parseUVIndex(uvs[uvi], uvLen));

				}

			}
		};
		state.startObject('', false);
		return state;

	} //


	class OBJLoader extends THREE.Loader {

		constructor(manager) {

			super(manager);
			this.materials = null;

		}

		load(url, onLoad, onProgress, onError) {

			const scope = this;
			const loader = new THREE.FileLoader(this.manager);
			loader.setPath(this.path);
			loader.setRequestHeader(this.requestHeader);
			loader.setWithCredentials(this.withCredentials);
			loader.load(url, function (text) {

				try {

					onLoad(scope.parse(text));

				} catch (e) {

					if (onError) {

						onError(e);

					} else {

						console.error(e);

					}

					scope.manager.itemError(url);

				}

			}, onProgress, onError);

		}

		setMaterials(materials) {

			this.materials = materials;
			return this;

		}

		parse(text) {

			const state = new ParserState();

			if (text.indexOf('\r\n') !== - 1) {

				// This is faster than String.split with regex that splits on both
				text = text.replace(/\r\n/g, '\n');

			}

			if (text.indexOf('\\\n') !== - 1) {

				// join lines separated by a line continuation character (\)
				text = text.replace(/\\\n/g, '');

			}

			const lines = text.split('\n');
			let line = '',
				lineFirstChar = '';
			let lineLength = 0;
			let result = []; // Faster to just trim left side of the line. Use if available.

			const trimLeft = typeof ''.trimLeft === 'function';

			for (let i = 0, l = lines.length; i < l; i++) {

				line = lines[i];
				line = trimLeft ? line.trimLeft() : line.trim();
				lineLength = line.length;
				if (lineLength === 0) continue;
				lineFirstChar = line.charAt(0); // @todo invoke passed in handler if any

				if (lineFirstChar === '#') continue;

				if (lineFirstChar === 'v') {

					const data = line.split(/\s+/);

					switch (data[0]) {

						case 'v':
							state.vertices.push(parseFloat(data[1]), parseFloat(data[2]), parseFloat(data[3]));

							if (data.length >= 7) {

								state.colors.push(parseFloat(data[4]), parseFloat(data[5]), parseFloat(data[6]));

							} else {

								// if no colors are defined, add placeholders so color and vertex indices match
								state.colors.push(undefined, undefined, undefined);

							}

							break;

						case 'vn':
							state.normals.push(parseFloat(data[1]), parseFloat(data[2]), parseFloat(data[3]));
							break;

						case 'vt':
							state.uvs.push(parseFloat(data[1]), parseFloat(data[2]));
							break;

					}

				} else if (lineFirstChar === 'f') {

					const lineData = line.substr(1).trim();
					const vertexData = lineData.split(/\s+/);
					const faceVertices = []; // Parse the face vertex data into an easy to work with format

					for (let j = 0, jl = vertexData.length; j < jl; j++) {

						const vertex = vertexData[j];

						if (vertex.length > 0) {

							const vertexParts = vertex.split('/');
							faceVertices.push(vertexParts);

						}

					} // Draw an edge between the first vertex and all subsequent vertices to form an n-gon


					const v1 = faceVertices[0];

					for (let j = 1, jl = faceVertices.length - 1; j < jl; j++) {

						const v2 = faceVertices[j];
						const v3 = faceVertices[j + 1];
						state.addFace(v1[0], v2[0], v3[0], v1[1], v2[1], v3[1], v1[2], v2[2], v3[2]);

					}

				} else if (lineFirstChar === 'l') {

					const lineParts = line.substring(1).trim().split(' ');
					let lineVertices = [];
					const lineUVs = [];

					if (line.indexOf('/') === - 1) {

						lineVertices = lineParts;

					} else {

						for (let li = 0, llen = lineParts.length; li < llen; li++) {

							const parts = lineParts[li].split('/');
							if (parts[0] !== '') lineVertices.push(parts[0]);
							if (parts[1] !== '') lineUVs.push(parts[1]);

						}

					}

					state.addLineGeometry(lineVertices, lineUVs);

				} else if (lineFirstChar === 'p') {

					const lineData = line.substr(1).trim();
					const pointData = lineData.split(' ');
					state.addPointGeometry(pointData);

				} else if ((result = _object_pattern.exec(line)) !== null) {

					// o object_name
					// or
					// g group_name
					// WORKAROUND: https://bugs.chromium.org/p/v8/issues/detail?id=2869
					// let name = result[ 0 ].substr( 1 ).trim();
					const name = (' ' + result[0].substr(1).trim()).substr(1);
					state.startObject(name);

				} else if (_material_use_pattern.test(line)) {

					// material
					state.object.startMaterial(line.substring(7).trim(), state.materialLibraries);

				} else if (_material_library_pattern.test(line)) {

					// mtl file
					state.materialLibraries.push(line.substring(7).trim());

				} else if (_map_use_pattern.test(line)) {

					// the line is parsed but ignored since the loader assumes textures are defined MTL files
					// (according to https://www.okino.com/conv/imp_wave.htm, 'usemap' is the old-style Wavefront texture reference method)
					console.warn('THREE.OBJLoader: Rendering identifier "usemap" not supported. Textures must be defined in MTL files.');

				} else if (lineFirstChar === 's') {

					result = line.split(' '); // smooth shading
					// @todo Handle files that have varying smooth values for a set of faces inside one geometry,
					// but does not define a usemtl for each face set.
					// This should be detected and a dummy material created (later MultiMaterial and geometry groups).
					// This requires some care to not create extra material on each smooth value for "normal" obj files.
					// where explicit usemtl defines geometry groups.
					// Example asset: examples/models/obj/cerberus/Cerberus.obj

					/*
			 * http://paulbourke.net/dataformats/obj/
			 * or
			 * http://www.cs.utah.edu/~boulos/cs3505/obj_spec.pdf
			 *
			 * From chapter "Grouping" Syntax explanation "s group_number":
			 * "group_number is the smoothing group number. To turn off smoothing groups, use a value of 0 or off.
			 * Polygonal elements use group numbers to put elements in different smoothing groups. For free-form
			 * surfaces, smoothing groups are either turned on or off; there is no difference between values greater
			 * than 0."
			 */

					if (result.length > 1) {

						const value = result[1].trim().toLowerCase();
						state.object.smooth = value !== '0' && value !== 'off';

					} else {

						// ZBrush can produce "s" lines #11707
						state.object.smooth = true;

					}

					const material = state.object.currentMaterial();
					if (material) material.smooth = state.object.smooth;

				} else {

					// Handle null terminated files without exception
					if (line === '\0') continue;
					console.warn('THREE.OBJLoader: Unexpected line: "' + line + '"');

				}

			}

			state.finalize();
			const container = new THREE.Group();
			container.materialLibraries = [].concat(state.materialLibraries);
			const hasPrimitives = !(state.objects.length === 1 && state.objects[0].geometry.vertices.length === 0);

			if (hasPrimitives === true) {

				for (let i = 0, l = state.objects.length; i < l; i++) {

					const object = state.objects[i];
					const geometry = object.geometry;
					const materials = object.materials;
					const isLine = geometry.type === 'Line';
					const isPoints = geometry.type === 'Points';
					let hasVertexColors = false; // Skip o/g line declarations that did not follow with any faces

					if (geometry.vertices.length === 0) continue;
					const buffergeometry = new THREE.BufferGeometry();
					buffergeometry.setAttribute('position', new THREE.Float32BufferAttribute(geometry.vertices, 3));

					if (geometry.normals.length > 0) {

						buffergeometry.setAttribute('normal', new THREE.Float32BufferAttribute(geometry.normals, 3));

					}

					if (geometry.colors.length > 0) {

						hasVertexColors = true;
						buffergeometry.setAttribute('color', new THREE.Float32BufferAttribute(geometry.colors, 3));

					}

					if (geometry.hasUVIndices === true) {

						buffergeometry.setAttribute('uv', new THREE.Float32BufferAttribute(geometry.uvs, 2));

					} // Create materials


					const createdMaterials = [];

					for (let mi = 0, miLen = materials.length; mi < miLen; mi++) {

						const sourceMaterial = materials[mi];
						const materialHash = sourceMaterial.name + '_' + sourceMaterial.smooth + '_' + hasVertexColors;
						let material = state.materials[materialHash];

						if (this.materials !== null) {

							material = this.materials.create(sourceMaterial.name); // mtl etc. loaders probably can't create line materials correctly, copy properties to a line material.

							if (isLine && material && !(material instanceof THREE.LineBasicMaterial)) {

								const materialLine = new THREE.LineBasicMaterial();
								THREE.Material.prototype.copy.call(materialLine, material);
								materialLine.color.copy(material.color);
								material = materialLine;

							} else if (isPoints && material && !(material instanceof THREE.PointsMaterial)) {

								const materialPoints = new THREE.PointsMaterial({
									size: 10,
									sizeAttenuation: false
								});
								THREE.Material.prototype.copy.call(materialPoints, material);
								materialPoints.color.copy(material.color);
								materialPoints.map = material.map;
								material = materialPoints;

							}

						}

						if (material === undefined) {

							if (isLine) {

								material = new THREE.LineBasicMaterial();

							} else if (isPoints) {

								material = new THREE.PointsMaterial({
									size: 1,
									sizeAttenuation: false
								});

							} else {

								material = new THREE.MeshPhongMaterial();

							}

							material.name = sourceMaterial.name;
							material.flatShading = sourceMaterial.smooth ? false : true;
							material.vertexColors = hasVertexColors;
							state.materials[materialHash] = material;

						}

						createdMaterials.push(material);

					} // Create mesh


					let mesh;

					if (createdMaterials.length > 1) {

						for (let mi = 0, miLen = materials.length; mi < miLen; mi++) {

							const sourceMaterial = materials[mi];
							buffergeometry.addGroup(sourceMaterial.groupStart, sourceMaterial.groupCount, mi);

						}

						if (isLine) {

							mesh = new THREE.LineSegments(buffergeometry, createdMaterials);

						} else if (isPoints) {

							mesh = new THREE.Points(buffergeometry, createdMaterials);

						} else {

							mesh = new THREE.Mesh(buffergeometry, createdMaterials);

						}

					} else {

						if (isLine) {

							mesh = new THREE.LineSegments(buffergeometry, createdMaterials[0]);

						} else if (isPoints) {

							mesh = new THREE.Points(buffergeometry, createdMaterials[0]);

						} else {

							mesh = new THREE.Mesh(buffergeometry, createdMaterials[0]);

						}

					}

					mesh.name = object.name;
					container.add(mesh);

				}

			} else {

				// if there is only the default parser state object with no geometry data, interpret data as point cloud
				if (state.vertices.length > 0) {

					const material = new THREE.PointsMaterial({
						size: 1,
						sizeAttenuation: false
					});
					const buffergeometry = new THREE.BufferGeometry();
					buffergeometry.setAttribute('position', new THREE.Float32BufferAttribute(state.vertices, 3));

					if (state.colors.length > 0 && state.colors[0] !== undefined) {

						buffergeometry.setAttribute('color', new THREE.Float32BufferAttribute(state.colors, 3));
						material.vertexColors = true;

					}

					const points = new THREE.Points(buffergeometry, material);
					container.add(points);

				}

			}

			return container;

		}

	}

	THREE.OBJLoader = OBJLoader;

})();

module.exports = exports = THREE.OBJLoader;